Most of what GMs can do is...be Daimons, and send Event RP messages from their characters.
Oh, and have their family details hidden.
Not exactly tailor-made for running portal events in arbitrary regions on arbitrary continents.
Since the wiki is mostly dead these days, I'm just gonna go and assume no one's made a record of what previous portal events have meant. Could you give a few further examples?
Can GMs spawn daimons? Because spawning some daimons, a daimon NPC troop leader, and using Event RPs, sounds like enough to me.
But maybe I'm not seeing the "cool" potential due to just not being aware of what kind of things were done in the past and thus what kind of things you'd be willing to do. I just remember being told that many times people don't even bother with RPing it, and that what happens is based on RPs, so...
I mean, I kinda like the concept behind it all, that some rare items can be used and have wild custom impacts, but the appreciation for it kind of sours when told that such power doesn't get the respect it would deserve, by players just using them without even bothering to put any RP around it.